Polyvinyl chloride (PVC) film has been used in film form for numerous applications, such as adhesive tapes, automotive pinstripes, dust covers and the like. A specific application of PVC film is in decorative borders and appliques as described in U.S. Pat. No. 4,900,604 to Martinez et al. PVC resin has to be highly plasticized to give it flexibility for these uses. The PVC is processed by premixing in plasticizers and stabilizers, then sheeting out the film in a calendering operation. When the film is laminated onto a liner, the film is held in a stretched conformation that is only released when the film is removed from the liner. In later use, the film may additionally be stretched during application. After time passes, the film "remembers" its relaxed state and shrinks. This is especially a problem in adhesive composite structures, such as adhesive tape or decorative borders or appliques. In such applications, the shrinking of the film causes a shear stress in the adhesive layer. When this happens, the product may fall off the substrate.
Ionomeric resins (such as the Surlyn.TM. family of resins, commercially available from E. I. DuPont de Nemours Co.) have been mainly exploited as a tough covering for sporting equipment such as golf balls, and as a heat-shrinkable plastic wrap component. In some cases, the cold temperature properties of ionomers have proved useful, as in U.S. Pat. No. 4,161,562. Ethylene-co-methacrylic acid copolymers have been blended, as in U.S. Pat. Nos. 3,445,546 and 3,869,422, and more recently U.S. Pat. No. 4,916,025. In the latter patent, Surlyn.TM. material was used only as a heat sealing outer layer, optionally blended with other resins to reduce cost. Given the recommended uses for Surlyn.TM. resins, one would not expect the filled material to act as a stand-alone conformable film.
U.S. Pat. No. 4,279,344 describes a peelable, heat-sealable packaging laminate. The inner sealing layer is formed from polypropylene or polyethylene/polypropylene copolymer blended with 15-35% Surlyn.TM. ionomer. The heat-sealed Surlyn.TM. film bonds are described as hand peelable. U.S. Pat. No. 4,835,025 describes a barrier laminate for essential oils/flavorings composed of paper substrate coated with nylon, which is coated with Surlyn.TM. resin and a coating of olefin (polylethylene) overall. The intermediate nylon or Surlyn.TM. film layer may be pigmented using a pigment such as TiO.sub.2 at 0.5-15%.
U.S. Pat. No. 4,653,752 describes a sport ball comprised of a plastic shell covered with a sewn cover. The shell is a blend of Surlyn.TM. resin with 25-50% ethylene-co-vinyl acetate (EVA). The Surlyn.TM. resin is described as providing strength and durability, while the EVA provides softness. These properties are noted for bulk-like materials such as spherical balls. Increasing EVA content leads to more rubbery, softer materials, while increasing Surlyn.TM. resin levels leads to harder, more resilient materials. Regarding additives, small amounts of other plastic polymers may be added without changing the characteristics significantly, and glass may be added as well.